1. Field of the Invention
The present invention is related to information handling systems, and, more specifically, to shutdown control of power supplies for the information handling systems.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems, e.g., computer, personal computer workstation, portable computer, computer server, print server, network router, network hub, network switch, storage area network disk array, RAID disk system and telecommunications switch.
An information handling system requires a power supply that converts utility power to voltages useable by the information handling system. However, when power is turned off to the power supply, the various power supply voltage rails get discharged based upon the load connected to them. If the power supply is quickly turned back on, the supply voltage rails may not fully discharge such that the rails do not go all the way down to substantially zero potential (or at least below 0.7 volts) before coming back up and returning to full power supply voltage levels. This can cause integrated circuit devices of the information handling system to latch-up, e.g., malfunction or assume an incorrect logic state. Certain complex logic arrays, e.g., CPLD require that the voltage to them must drop below 0.7 volt in order for them to properly reload an operating program.
Therefore, what is needed is a solution for insuring that when a power supply of an information handling system is turned off, its output voltage(s) always is less than a minimum voltage level before being re-energized to full operating output voltage(s).